diff --git a/cmd/gazelle/integration_test.go b/cmd/gazelle/integration_test.go
index ff8ec12d0..ea0be886b 100644
--- a/cmd/gazelle/integration_test.go
+++ b/cmd/gazelle/integration_test.go
@@ -2975,72 +2975,3 @@ go_repository(
 		},
 	})
 }
-
-func TestMatchProtoLibrary(t *testing.T) {
-	files := []testtools.FileSpec{
-		{
-			Path: "WORKSPACE",
-		},
-		{
-			Path: "proto/BUILD.bazel",
-			Content: `
-load("@rules_proto//proto:defs.bzl", "proto_library")
-# gazelle:prefix example.com/foo
-
-some_rule(
-	name = "gen_proto",
-	out = "foo.proto",
-)
-
-proto_library(
-	name = "existing_proto",
-	srcs = ["foo.proto"],
-)
-`,
-		},
-	}
-	dir, cleanup := testtools.CreateFiles(t, files)
-	defer cleanup()
-
-	args := []string{"update"}
-	if err := runGazelle(dir, args); err != nil {
-		t.Fatal(err)
-	}
-
-	testtools.CheckFiles(t, dir, []testtools.FileSpec{
-		{
-			Path: "proto/BUILD.bazel",
-			Content: `
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
-load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
-load("@rules_proto//proto:defs.bzl", "proto_library")
-# gazelle:prefix example.com/foo
-
-some_rule(
-    name = "gen_proto",
-    out = "foo.proto",
-)
-
-proto_library(
-    name = "existing_proto",
-    srcs = ["foo.proto"],
-    visibility = ["//visibility:public"],
-)
-
-go_proto_library(
-    name = "proto_go_proto",
-    importpath = "example.com/foo",
-    proto = ":existing_proto",
-    visibility = ["//visibility:public"],
-)
-
-go_library(
-    name = "go_default_library",
-    embed = [":proto_go_proto"],
-    importpath = "example.com/foo",
-    visibility = ["//visibility:public"],
-)
-`,
-		},
-	})
-}
diff --git a/language/proto/kinds.go b/language/proto/kinds.go
index aef1518e2..d4d9c0179 100644
--- a/language/proto/kinds.go
+++ b/language/proto/kinds.go
@@ -19,7 +19,6 @@ import "github.com/bazelbuild/bazel-gazelle/rule"
 
 var protoKinds = map[string]rule.KindInfo{
 	"proto_library": {
-		MatchAttrs:    []string{"srcs"},
 		NonEmptyAttrs: map[string]bool{"srcs": true},
 		MergeableAttrs: map[string]bool{
 			"srcs": true,
diff --git a/merger/merger.go b/merger/merger.go
index dbd2fb23b..7993eba07 100644
--- a/merger/merger.go
+++ b/merger/merger.go
@@ -38,7 +38,6 @@ package merger
 
 import (
 	"fmt"
-	"sort"
 	"strings"
 
 	"github.com/bazelbuild/bazel-gazelle/rule"
@@ -223,15 +222,19 @@ func Match(rules []*rule.Rule, x *rule.Rule, info rule.KindInfo) (*rule.Rule, er
 
 	for _, key := range info.MatchAttrs {
 		var attrMatches []*rule.Rule
+		xvalue := x.AttrString(key)
+		if xvalue == "" {
+			continue
+		}
 		for _, y := range kindMatches {
-			if attrMatch(x, y, key) {
+			if xvalue == y.AttrString(key) {
 				attrMatches = append(attrMatches, y)
 			}
 		}
 		if len(attrMatches) == 1 {
 			return attrMatches[0], nil
 		} else if len(attrMatches) > 1 {
-			return nil, fmt.Errorf("could not merge %s(%s): multiple rules have the same attribute %s", xkind, xname, key)
+			return nil, fmt.Errorf("could not merge %s(%s): multiple rules have the same attribute %s = %q", xkind, xname, key, xvalue)
 		}
 	}
 
@@ -245,23 +248,3 @@ func Match(rules []*rule.Rule, x *rule.Rule, info rule.KindInfo) (*rule.Rule, er
 
 	return nil, nil
 }
-
-func attrMatch(x, y *rule.Rule, key string) bool {
-	xValue := x.AttrString(key)
-	if xValue != "" && xValue == y.AttrString(key) {
-		return true
-	}
-	xValues := x.AttrStrings(key)
-	yValues := y.AttrStrings(key)
-	if xValues == nil || yValues == nil || len(xValues) != len(yValues) {
-		return false
-	}
-	sort.Strings(xValues)
-	sort.Strings(yValues)
-	for i, v := range xValues {
-		if v != yValues[i] {
-			return false
-		}
-	}
-	return true
-}
diff --git a/merger/merger_test.go b/merger/merger_test.go
index 4af976577..658b8d2dc 100644
--- a/merger/merger_test.go
+++ b/merger/merger_test.go
@@ -969,15 +969,6 @@ go_binary(name = "y")
 go_binary(name = "z")
 `,
 			wantError: true,
-		}, {
-			desc:      "srcs match",
-			gen:       `proto_library(name = "proto1", srcs = ["foo.proto", "bar.proto"])`,
-			old:       `proto_library(name = "proto2", srcs = ["bar.proto", "foo.proto"])`,
-			wantIndex: 0,
-		}, {
-			desc: "importpath match",
-			gen:  `go_proto_library(name = "go_proto1", importpath="example.com/foo")`,
-			old:  `go_proto_library(name = "go_proto2", importpath="example.com/foo")`,
 		},
 	} {
 		t.Run(tc.desc, func(t *testing.T) {